03 August 2020, 23:34 | #1 |
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Does it make sense to use BOBs on a 030?
Hello, let's suppose you want to make a game such as Final Fight, targeted at AGA and fast 030 CPUs. Would you use the blitter or rather the CPU to display the fighters?
In general, given the same type of game, what is the least powerful CPU that would make you choose not to use the blitter? I know that the answer depends on a number of other factors, but I'd like to read your opinions. Last edited by Quagliarulo; 04 August 2020 at 01:13. |
04 August 2020, 07:57 | #2 |
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Short answer: Anytime I have real fast RAM.
Long answer: Depends on colors/resolution. If I'm working in a lores screenmode in best fetchmode there's always some free time left over for the blitter to do *SOMETHING*. The faster your CPU gets, the more it's held back by bandwidth to chipmem. You should always max out what the blitter can do without stealing cycles first, then do the rest with the CPU copying from fast memory. The blitter is crippled by being essentially the old ECS Agnus blitter, but it has the advantage of having access to DMA time that the CPU doesn't. |
04 August 2020, 08:27 | #3 |
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don't forget that the blitter not only copies but shifts & masks.
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04 August 2020, 13:44 | #4 |
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Very much this!!
If you're doing everything with the CPU, you'll need either preshifted copies of each frame of graphics (ZX Spectrum style ) or you'll have to shift all the bits in real time as you're drawing them. If you have enough Fast RAM for the 16 copies of all the graphics and mask bits you'll need, then even the stock 14mhz CPU inside an A1200 should beat the blitter by a decent margin. And, you can always use the blitter as well to have even more going on screen. B |
05 August 2020, 17:17 | #5 |
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Can A1200s and A4000s have any slow RAM fitted into them?
Which machines can? |
06 August 2020, 18:05 | #6 | |
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Quote:
Could you fit slow RAM by wiring it directly into FatGary/Gayle? Probably -- but why would you do that? |
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